Heat exchanger



J. H. BLANCHARD ET AL Apri 28, 1970 HEAT EXCHANGER Filed Sept; 4, 1968 2 Sheets-Sheet 1 N Y m m C MN J R AE W O MLW .r, 1 w BA i A H A E W 2/ 0 w April 1970 J. H. BLANCHARD ET AL 3,508,606

HEAT EXCHANGER Filed Sept. 4, 1968 2 Sheets-Sheet 2 JOHN LANCHARD GEORG ANDERSON ATTORNEY United States Patent 3,508,606 HEAT EXCHANGER John H. Blanchard, Wallingford, and George A. Anderson, Northford, Conn., assignors to Olin Mathieson Chemical Corporation, a corporation of Virginia Filed Sept. 4, 1968, Ser. No. 757,312 Int. Cl. F28f 1/40, 9/00 US. Cl. 165-145 3 Claims ABSTRACT OF THE DISCLOSURE As is known in the heat exchanger art, the greatest heat exchange is achieved by providing the maximum possible area of material across which the desired heat exchange may take place. Various devices have been employed to so increase the material area, such as, for example, fins or corrugations across which pass the media between which the heat exchange is to take place. However, it has been found that greatly increased heat transfer can be achieved by instead employing a body of pervious material or a porous body having interconnected voids. Such a body of pervious material presents a large number of faces for heat exchange purposes, as well as other advantages to be discussed shortly.

By the instant invention, there is provided a method of producing a heat exchanger having a unique configuration and arrangement of such a pervious body. Such a heat exchanger has been tested and found to result in greatly increased heat exchange properties.

The concept of the present invention may be employed in heat exchangers in any desired shape, but is particularly adapted to tubular heat exchangers. As is known in the art, the use of heat exchangers of a tubular configuration is highly advantageous in certain environments, for example, where the exchanger is so situated that it is immersed in one of the heat exchange media. The tubular exchangers presently in use in such an environment commonly comprise two concentric tubes, often with corrugations in the annulus between the tubes to turbulate the circulated medium; the flow path in the annulus being substantially axial along the tubes.

In the concept of the instant invention, however, there is provided a method of producing a heat exchanger and a heat exchanger in which not only the heat exchange area is increased, but the flow of the heat exchange medium is directed in a path through the spaces formed by the spaced apart tubes or elements. The advantages resulting are achieved by the provision of a body of pervious material situated within the tubes or elements, forming channels to serve as inlet and outlet for a heat exchange medium to pass through the aforementioned pervious body. The inlet channel also serves to provide uniform distribution through the pervious body and the outlet channel serves to provide uniform collection of the medium after it has passed through the pervious body. While the usual expedient is to arrange the tubes so that they are longitudinally spaced apart, the concept of this invention is equally applicable to other arrangements of tubes or elements within a shell.

It is accordingly an object of this invention to provide a heat exchanger which is compact and yet capable of high efficiency and low pressure drop.

It is a further object to provide such a heat exchanger 3,508,606 Patented Apr. 28, 1970 comprising a first and second conduit means wherein said first conduit means has a plurality of spaced apart elements each containing at least one pervious body and an inlet means and outlet means thereto.

It is a still further object to provide a unique method of producing such a heat exchanger.

Other objects will become apparent to those skilled in the art from a consideration of the details of several specific examples illustrated in the drawings in which:

FIGURE 1 is a perspective view of a first embodiment of a heat exchanger produced in accordance with the method of this invention.

FIGURE 2 is a perspective view of a single heat exchange element with the end unsealed.

FIGURE 3 is a perspective view of an end of the heat exchange element in FIGURE 2 with the end sealed.

FIGURE 4 is a perspective view of an alternative embodiment of sealing the heat exchange element of FIGURE 2.

FIGURE 5 is a perspective view of a plurality of heat exchange elements interconnected including inlet means and outlet means.

FIGURE 6 is an axial cross section of a second embodiment of the tubular configuration of FIGURE 5.

FIGURE 7 is a cross sectional view of the heat exchange element of FIGURE 2 containing a plurality of pervious bodies.

FIGURE 8 is a perspective view of an alternative embodiment of the heat exchanger of FIGURE 1.

FIGURE 9 is a view of a single heat exchange element showing cores positioned therein.

Several embodiments of a heat exchanger will first be described followed by a description of the method of producing each.

Thus, a first embodiment of heat exchanger is shown in FIGURE 1, and is designated generally by 10. As indicated hereinbefore, the heat exchanger 10 may be employed in applications where it is immersed in one of the heat exchange media. Thus, a first heat exchange medium, not shown, for example, that to be employed in heating or cooling, may surround the heat exchanger 10. The first heat exchange medium is introduced into the heat exchanger 10 at one end, as shown by the arrow 11, and exits from the opposite end as shown by the arrow 12. Obviously, required fittings, not shown, may be employed. A second heat exchange medium, not shown, for example the medium to be cooled or heated, enters the heat exchanger 10 through any suitable fitting in the direction of the arrow 13, is circulated through the heat exchanger, and exits through a suitable fitting in the direction of the arrow 14. Thus, heat exchange may take place between the second medium and the first medium flowing through the exchanger. It will be obvious that any desired media might be employed in the instant heat exchanger; for example, in application in an automotive cooling system, the medium introduced at 11 may be water and the medium introduced at 13 may be oil.

Naturally, the heat exchanger 10 need not be actually immersed in one of the heat exchange mediums as in the foregoing illustration, but may be employed in a standard fashion wherein both mediums to be circulated are drawn from a remote outside source, i.e. where one medium does not surround the exchanger.

The construction of heat exchanger 10 is shown in detail in FIGURE 1 wherein it may be seen that the heat exchanger 10 comprises conduit means 15 positioned within conduit means 16 leaving a space therebetween. Suitable inlet and outlet fittings 17 and 18 are provided at opposite ends of the heat exchanger. Naturally, however, inlet and outlet fittings 17 and 18 may be provided in any convenient location other than at the opposing ends. Conduit means 15 comprises a plurality of elements 21, as shown in FIGURE 2, and said elements when taken together may hereinafter be referred to as the module. Openings 19 and 20 are provided for an inlet and outlet in each element 21; said openings and said inlet and outlet constituting an inlet means and outlet means respectively. The inlet comprises a manifold 22 having an inlet portion 23 extending through a suitable opening in the wall of the conduit means 16 and likewise the outlet comprises a manifold (not shown) having an outlet portion 24 extending through a suitable opening in the wall of conduit means 16.

Naturally inlet and outlet portions per se need not be employed i.e., suitable connections may be made directly to the aforementioned manifolds through the opening in the wall of conduit means 16.

Referring now to FIGURE 2, a pervious body 25 is positioned within each element 21 defining channels 26 and 27. Channel 26 communicates with inlet portion 23 through manifold 22 and channel 27 communicates with outlet portion 24 through the manifold not shown. Thus the medium introduced in inlet portion 23 flows through a manifold 22 into channel 26 thence through the circuitous paths within the pervious body 25 into channel 27 whence it may pass through the manifold not shown to outlet portion 24. It will be evident that the provision of the pervious body 25 provides increased heat exchange surfaces for contact by the circulated medium but due to the circuitous flow paths present by previous body 25 also provides controlled and uniform distribution of the medium through the entire pervious body 25 with a minimum pressure drop. Thus, it may be seen that channel 26 provides for controlled distribution of the heat exchanger medium and channel 27 provides for controlled collection of the medium introduced.

The aforementioned element 21 is sealed at each end in any appropriate manner such as, for example, by metallically bonding a cap 28 thereto, as shown in FIGURE 3 or by actually compressing and metallically bonding the sides of the element together as shown by reference number 29 in FIGURE 4. The aforementioned methods of bonding may be, for example, welding or brazing the cap to the body of pervious material within the element 21 and/or to the sides of the element, and likewise by welding or brazing the sides of the element together should this method be employed.

Other alternative embodiments of the heat exchanger, more specifically the first conduit means 15, are shown in FIGURES through 7. Referring now to FIGURE 5, a plurality of heat exchange modules may be manifolded together. In this embodiment the outlet manifold does not communicate with outlet portion 24 as shown in FIGURE 1 but communicates with one or more modules. More specifically the medium introduced after passing through the channel 26 and pervious body 25 into channel 27 in element 21 in the first module 580 then passes into auxiliary manifold 130, whereupon the described flow pattern is similarly repeated, as indicated by arrows, through a second module 581 and a third module 582, and finally to outlet portion 24 via a manifold 131. Naturally, this embodiment is not limited to the three modules as just described but any number of modules, limited only to practicality, may be employed with a repetition of the flow of the medium introduced as described.

A third alternative embodiment of the present invention is shown in FIGURE 6. As is shown in FIGURE 6, the first conduit means rather than comprising a rectangular arrangement as in FIGURES 1 and 5 may be positioned in a circular arrangement. Manifold 232 and manifold 233 are likewise in a circular arrangement and in communication with channels 234 and 235 respectively and to an inlet and outlet (not shown) respectively. A plurality of modules may also be provided in this emmodiment the same as shown in FIGURE 5.

As is apparent a plurality of pervious bodies 325 may also be provided if desired in each element 21 as shown in FIGURE 7 as a fourth alternative embodiment.

A fifth alternative embodiment of the present invention is shown in FIGURE 8. In this embodiment heat exchanger 436 is provided with a box or manifold 437 having an inlet 438 and an outlet 439. A medium to be heated or cooled fiows into the box 437 through inlet 438, into inlet channel 440 through pervious body 425 to collect in outlet channel 441 whence it passes back into box 437 and to outlet 439. The end portions of elements 421 are sealed only at the pervious body so that ingress and egress may occur only at the aforementioned channels. In addition, a baffle 442 permits entry of the medium only to inlet channel 440 and correspondingly permits outlet of the media introduced at inlet channel 440 only through outlet channel 441. In addition, a header 443 being in abutting arrangement with channels 440 and 441 limits flow of the medium introduced at inlet channel 440 through pervious body 425. If desired baffles may also be provided on the shell side in this embodiment.

Naturally, a plurality of modules may be manifolded together as shown in FIGURE 5 thereby providing an increase in area of the aforementioned previous body, i.e., since each module contains at least one pervious body through which the medium passes before exiting from outlet channel 441.

Still a sixth alternative embodiment may be as shown in FIGURE 7, wherein channels 326, 327 may serve as either outlet or inlet channels together. As is shown, element 21 contains a plurality of pervious bodies defining channels therein. Thus, two inlet means and a single outlet means, or correspondingly two outlet means and a single inlet means may be provided. Thus channels 326 and 327 may serve together as outlet channels and channel 544 may serve as a single inlet channel or vice versa. Naturally, if desired, a plurality of modules may be suitably manifolded together.

It is to be understood that the concept of this invention need not be limited to the particular configurations indicated above. For example, any desired shape of the element may be provided, with the pervious body shaped accordingly to fit. Furthermore, as aforementioned, any number of elements may be employed, the exchanger may be used for either heating or cooling, and the elements may be of any desired cross-section. In addition, at least one porous metal body may also be provided between the first and second conduit means if desired.

The present invention need not be provided with conduit means 16, i.e., the outside tube or shell, but also embraces positioning conduit means 15 within existing structures such as, for example, tanks, automotive transmissions, etc. Hence, as is readily apparent, a second conduit means, per so, need not be required.

Considering now the novel method by which the heat exchangers previously described may be produced, reference may be had to FIGURES 2 and 9. Since production of the alternative embodiments of the heat exchanger element 21 is basically similar to that of FIGURE 2, the discussion which follows will be directed only to the latter, it being understood that production of the alternative embodiments is similar unless indicated to the contrary.

As will be understood various combinations of metals may be utilized in forming the heat exchangers according to the instant invention; and accordingly the solid portions and the pervious body may be of the same metal or alloy, or the pervious structure and the solid member may be comprised of different compositions. For example, both the pervious body and solid portions may be formed of the same stainless steels, coppers, brass, carbon steels, aluminums or variou combinations thereof. As will be evident, the ultimate use of the resultant structure determines the specific combination of alloys to be employed.

The production of the pervious body is most flexible; for example, it may be produced by a process wherein particles, frequently spherical, are poured by gravity into an appropriately shaped confined space and usually vibrated to cause the particles to compact uniformly. As is obvious, the choice of particle size will largely determine the size of openings of the resulting pervious body. The body of particles so packed is then treated in accordance with any of the well known metallurgy practices, e.g., sintering, welding, brazing or soldering employing an appropriate coating to produce a metallic bond between the particles. Thus, there is provided a pervious body whose bulk density, or apparent density, is a fraction of the density of the metal or alloy from which the particles are obtained. Furthermore, such process results in a metallic bond between the previous body and its container.

Referring now to FIGURE 9 it will be seen that a heat exchanger module may be produced in accordance with this invention by a unique method. The element 21 is positioned on a suitable support, and cores 45 and 46 placed therein as shown in FIGURE 9. Conversely the core 45 and 46 may just be positioned and then element 21 slipped down over them. Either method lends itself to producing channels within a single element, or simultaneously a plurality of elements manifolded together, it being understood that appropriate openings for inlet means and outlet means may first be formed in any conventional fashion, or that element 21 may be purchased extruded with the openings already present. Naturally, element 21 need not be an extrusion, as aforementioned, but may be formed in any appropriate manner such as forming from sheet stock, etc.

As shown in FIGURE 9, cores 45 and 46 project above the upper end of element 21. And, as seen in FIGURE 9, cores 45 and 46 are spaced apart to form the channels previously discussed. These cores may be of any desired size or shape depending upon the channel areas and configuration desired. For reasons to become evident shortly, cores 45 and 46 are of a material which would be unaffected by any of the previously discussed methods of achieving a metallic bond, e.g., carbon or ceramic, or of metal coated with any of the well-known stop-off materials, e.g., titanium dioxide or graphite to prevent a metallic bond between the metal core and any other body. Naturally, additional cores may be employed if additional channels, or enlarged channel areas are desired.

Particulate material may now be poured into element 21 in the volume not occupied by cores 45 and 46. The particulate material will be poured to a level short of the upper end of the element 21 a distance suitable to allow for subsequent sealing. The particulate material introduced may not flow through the Openings 19 and 20 in element 21 for such openings would be covered by cores 45 and 46. Following any of the metallurgical processes previously described, the particulate material may be treated to achieve a metallic bond between the various particles and between the particulate material and element 21. No metallic bond will be treated between the resulting pervious body 25 and cores and 46 due to the charactor of the core indicated previously. Cores 45 and 46 may then be removed, as by pulling them out with an appropriate tool inserted in openings 47 and 48, respectively of cores 45 and 46. Element 21 may now be sealed in any appropriate method as aforementioned. A plurality of elements 21 may now be manifolded together as in any of the aforementioned embodiments to thereby form conduit means 15 and then conduit means 15 may be inserted into conduit means 16 and suitably secured, as by brazing, soldering, or welding into place. Addition of the required fittings completes the fabrication and the heat exchanger is ready for use.

Thus, the instant invention provides for extreme design flexibility and is readily applicable to manifolding a plurality of modules together. Ease of fabrication and repair is readily apparent, permitting fabrication, or disassembly for repair or replacement, of relatively small units and later assembly into larger size heat exchangers. Headers may be eliminated and size and weight of the exchanger is thereby reduced. If desired long modules may be produced and cut to length for later sealing and assembly, thereby allowing for increased mill capacity.

While we have shown and described different desired embodiments which result from the method of this invention it is to be understood as for the purpose of illustration only and that various changes and modifications may be made in the described method without departing from the spirit and scope of the invention as said further in the appended claims.

What is claimed is:

1. An apparatus for circulation of a first heat exchange medium comprising:

(A) a conduit means having a plurality of spaced apart elements to form a row for conveying a heat exchange medium;

(B) at least one body of pervious, heat conductive material within each said element and joined by a metallic bond thereto each said element further including,

(1) at least one first channel for controlled distribution of said medium entering said conduit means,

(2) at least one second channel for controlled collection of said medium being spaced apart from said first channel by said body of pervious material,

(C) a first manifold communicating with said first channel and a second manifold communicating with said second channel;

(D) an additional conduit means having at least one additional row of additional said elements operatively connected to said second manifold so that said second manifold communicates with said first channel of said additional row, and

(E) a third manifold communicating with said second channel of said additional row.

2. An apparatus in accordance with claim 1 comprising one said first channel and one said second channel.

3. An apparatus in accordance with claim 2 wherein said conduit means and said additional conduit means is a first conduit means, and wherein said apparatus includes a second conduit means having an inlet and outlet, said first conduit means being positioned within said second conduit means thereby forming a pace therebetween for conveying a second heat exchanger medium in heat exchange relationship with said first heat exchange medium.

References Cited UNITED STATES PATENTS 2,155,666 4/1939 Leidig l43 3,289,755 12/1966 Jacobs l65145 2,893,702 7/1959 Richardson 165-180 X 3,331,435 7/1967 Valyi l65-l80 X 3,339,260 9/1967 Burne et al l65180 X 3,364,951 1/1968 Burne et al 165l80 X ROBERT A. OLEARY, Primary Examiner A. W. DAVIS, JR., Assistant Examiner US. Cl. X.R. 165-150, 165, 176, 180, 181 

